Cleaning composition and method



or less rapid rate.

- erates over into the radiator.

Patented Nov. 1, 1938 UNITED STATES PATENT OFFICE V 2,135,066 OLEANING COMPOSITION AND METHOD Carl Winning, Union, and John B. Holtzclaw, Boselle, N. J., assignors to Standard Oil Development Company, a corporation of Delaware No Drawing.

2 Claim.

In any equipment charged with water, parj ticularly if of iron, corrosion occurs at a more If of a ferrous metal, the corrosion results in the formation of rust and while a portion of this corrosion product adheres to the surfaces being afiected, a large part of it breaks loose in the form of either fine flakes 01' powder and tends to settle to the bottom of the system. At the same time oil and grease, employed in lubricating mechanical parts adjacent to the water unit, find their way into the system and there become mixed with the rust. Furthermore, in the case of such equip.- ment as automobile radiators, dust and dirt from thesurrounding atmosphere collect in the water.

This mixture of rust, dirt, oil and grease gradually accumulates in the more or less dead spaces in the hydraulic system where agitation is not sufliciently violent to keep the solid particles in suspension. In time these deposits become quite tough as they are consolidated by the oily and greasy material.

The problem is further complicated in automotive cooling systems in that anti-freeze com-.

positions frequently contain certain oils which are added to reduce the corrosion normal to the unprotected anti-freeze agent. These oils appear to have a specific afiinity for rust and are extracted quite selectively from the liquid medium by the deposits already present Such deposits in cooling systems naturally reduce the emciency of the system in proportion to the area of cooling surface they cover. In addition, a muchmore serious trouble may be expected in automotive units for in. these it is not unusual that small portions of the deposits break loose and are carried in the form of sticky agglom- Here the material lodges in the fine passages and stops up a portion of the radiator. In a very short time a large part of the coolingv unit is thus rendered ineffective.

Many compositions have been proposed for cleaning hydraulic systems and most of these are in essence mild alkalies which exert limited ability in loosening the deposits and permitting them to be flushed out. The utility of suchmaterials is not very great and only deposits which Application November Serial N0. 754,467

have been but slightly consolidated with oily ma-- terial are affected by alkalies.

Somewhat greater success has been obtained by the use of organic solvents designed to dissolve out the oily material and thus make possible the more easy deflocculation of the rust accumulation. Most of the solvents employed, such as kerosene, coal tar solvents, alcohol, etc are not as successful as might be expected and it frequently happens that they merely succeed in breaking up the deposits into smaller agglomerates which in turn stop up the radiator 'as outlined above. The case is rather exceptional in which the use of these materials either by themselves or together with alkalies succeeds in removing all of the rusty material without endangering the radiator.

It has been found in the study of these phenomena that ifiatty materials are present as binding agents they are gradually converted to iron soaps by interaction with the rust. There are. alsoindications that mineral oils, presumably through oxidation, become reactable and form similar soaps. These soaps are very sticky and form extremely effective binders for rust and dirt accumulations. Furthermore, they are not sufficiently soluble in any of the solvents which have been employed in the past to make their removal thereby possible. Consequently efiicient rust removal has heretofore been impossible By. studying the solubility characteristics of these soaps it has been discovered that they are quite soluble in chlorinated organic compounds such as carbon tetrachloride, chloroform, chlorobenzene, chlorinated naphthalene and the like. 015 much greater eilicacy are materials which contain, in addition to chlorine, oxygen groupings. Thus BB dichlorethyl ether is exceptionally useful for dissolving such iron soaps and possesses the additional valuable property 'of not merely dissolving all the binder but also of so wetting the rust and dirt that they may easily be floated away in a subsequent flushing operation.

It is preferred to use, together with the chlorinated ether, kerosene or other hydrocarbon compound of similar boiling range in suflicient proportion to give a mixture having a specific gravity approximately the same as water, or best only slightly over 1 so that the mixture may be held in suspension in the cooling system very easily by only moderate agitation. Actual emulsiflcation, however, is to be avoided since emulsions are not eiiiclent cleansers.

Most chlorinated organic compounds slowly hydrolyze in the presence of water with the liberation of hydrochloric acid. It is therefore desirable to employ alongwith them a small amount of alkali to neutralize any acid formed. Fur-- thermore, as pointed out above, most alkalies possess a certain scouring action which makes their use along with the solvent even more'desirable. While it has been common practice to employ as alkalies such materials as sodium carbonate and sodium silicate, it has been found that trisodium phosphate is preferable inasmuch.

Per cent Dichlorethyl ether '10 Kerosen 30 To 12 fluid ounces of this mixture grams of trisodium phosphate are added either as such or in water solution.

In cleaning an automobile cooling system this composition is added directly to the water in the radiator and may be left therein for some 30 minutes to a number of days. During this period the rusty deposits are loosened and the rust is dispersed as a fairly stable suspension throughout the water in the system. The system is then drained, flushed with clean water several times and is then ready to resume operation. In most cases 30 minutes is quite sufiicient for loosening all the rusty material, but it is often more convenient from a marketing standpoint to place the composition in a car and tell the driver to return in two or three days to have his car flushed out. If, on the other hand, it appears desirable to do a quick cleaning Job in 20 to 30 minutes it is best to add the liquid components to the water in the cooling system, agitate well for 20 to 30 minutes, then introduce the trisodium phosphate, and after another 10 minutes of operation, drain and flush. The same general procedure is applicable to the cleaning of other hydraulic systems.

In some cases, the efliciency of the composition may be enhanced by the addition of penetrating agents such as sulfonated materials of the sulfonated naphthalene, sulfonated fatty oil or sulfonated mineral oil type.

The foregoing description is merely illustrative and various changes and alternative arrangements may be made within the scope of the appended claims in which it is our intention to claim all inherent novelty in the invention broadly as the prior art permits.

We claim:

1. A rust removing composition comprising b-b-dichlorethyl ether and kerosene in the ratio of about :30, said composition also containing about 50 grams of trisodium phosphate per 12 fluid ounces of the ether-kerosene solution.

2. The method of removing rust, grease, iron soaps, dirt, and similar accumulations from surfaces coated therewith, which comprises contacting said surfaces with water containing in suspension a composition comprising b-b-dichlorethyl ether and kerosene in the ratio of about 70:30, said composition also containing about 50 grams of trisodium phosphate per 12 fluid ounces of the ether-kerosene solution, whereby any acid formed by the hydrolysis of the dichlorethyl ether is neutralized by the trisodium phosphate.

CARL WINNING. JOHN B. HOLTZCLAW. 

